This invention generally relates to the art of electrical connectors and, particularly, to a jack assembly which includes a contact switching system for receiving a coaxial plug.
One type of jack assembly is designed for receiving a pin-type coaxial plug. The plug is inserted into an opening at the outside of the jack and into a cavity or plug-receiving chamber inside a dielectric housing of the jack. The housing mounts a plurality of terminals which are exposed within the chamber in the path of movement of the coaxial plug, whereby the plug engages the contacts to effect various electrical functions One pair of fixed and movable contacts may effect a switching function when the coaxial plug is inserted into the plug-receiving chamber of the jack housing.
One of the problems with switching contacts in jacks of this type is to maintain or ensure good electrical engagement between the movable and fixed contacts. The engaging surfaces of the contacts often become contaminated which deteriorates the effectiveness of the contact coupling therebetween. This contamination is particularly prevalent when the contacts are located within the plug-receiving chamber which is exposed for receiving the coaxial plug. Attempts have been made to provide a wiping action between the engaging surfaces of the movable contacts and the fixed contacts to counteract such contamination. However, most such jack assemblies are extremely small due to the ever-increasing miniaturization of such connector assemblies. The compact envelope afforded by such miniature constructions results in extremely small plug-receiving chambers and leave little room for providing adequate wiping actions within the chambers. The present invention is directed to solving these problems in an improved jack assembly of the character described.
An object, therefore, of the invention is to provide a new and improved jack assembly which includes a contact switching system for receiving a coaxial plug.
In the exemplary embodiment of the invention, the jack assembly includes an insulative housing having a plug-receiving chamber with an opening for receiving the coaxial plug in a plug-insertion direction. A fixed terminal is mounted on the housing and has a fixed switch contact portion located outside the plug-receiving chamber. A movable terminal is mounted on the housing and includes a spring arm at least partially located inside the plug-receiving chamber in the path of insertion of the coaxial plug, and a movable switch contact portion is connected to the spring arm for movement therewith into and out of engagement with the fixed contact portion of the fixed terminal. The movable switch contact portion is located outside the plug-receiving chamber.
With the above structure, engagement of the coaxial plug with the spring arm of the movable terminal inside the plug-receiving chamber is effective to cause the movable switch contact portion of the movable terminal to move relative to the fixed switch contact portion of the fixed terminal outside the plug-receiving chamber. Therefore, the size and/or shape of the contact portions of the terminals outside the chamber are not restricted by the size and/or shape of the chamber, itself.
According to one aspect of the invention, the movable switch contact portion of the movable terminal and the fixed switch contact portion of the fixed terminal comprise generally planar plates having interengaging wiping surfaces of substantial size which wipe over each other when the contact portions move relative to each other.
According to another aspect of the invention, the movable terminal is generally U-shaped to define a pair of legs. One leg is fixed to the housing. The other leg forms the spring arm of the movable terminal, with the spring arm at least partially located inside the plug-receiving chamber in the path of insertion of the coaxial plug. The movable switch contact portion extends from the other leg toward the fixed switch contact portion outside the chamber.
According to a further aspect of the invention, the spring arm of the movable terminal is pivotally movable upon engagement by the coaxial plug, about a pivot axis which extends generally perpendicular to the plug-insertion direction of the coaxial plug. The movable switch contact portion of the movable terminal slides over the fixed switch contact portion of the fixed terminal in a direction generally parallel to the plug-insertion direction of the coaxial plug.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.